/* Code authors: Masum Hasan, Cengiz Ozel, Sammy Potter
ROC-HCI Lab, University of Rochester
Copyright (c) 2023 University of Rochester

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
THE SOFTWARE. */


/* ==========================================================================
   SOPHIE Landing Page - Healthcare Theme
   ========================================================================== */

html {
    scroll-behavior: smooth;
}

.landing-page {
    --primary: #0B6E99;
    --primary-dark: #085A7D;
    --primary-light: #1A96C8;
    --accent: #00B4A6;
    --accent-light: #E0F7F5;
    --bg: #F8FAFB;
    --bg-alt: #EEF4F7;
    --card-bg: #FFFFFF;
    --text: #1A2332;
    --text-secondary: #5A6B7F;
    --text-muted: #94A3B8;
    --border: #E2E8F0;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 16px rgba(11,110,153,0.08);
    --shadow-lg: 0 12px 40px rgba(11,110,153,0.1);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;

    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background-color: var(--bg);
    color: var(--text);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.landing-page.dark {
    --bg: #1A2332;
    --bg-alt: #0F172A;
    --card-bg: #1E293B;
    --text: #F1F5F9;
    --text-secondary: #94A3B8;
    --text-muted: #64748B;
    --border: #334155;
}


/* ==========================================================================
   Navigation
   ========================================================================== */

#flatNav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 1rem 2rem;
    transition: background 300ms ease, box-shadow 300ms ease, padding 300ms ease;
    background: transparent;
}

#flatNav.scrolled {
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
    padding: 0.65rem 2rem;
}

.nav-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.65rem;
    text-decoration: none;
    color: white;
    transition: color 300ms ease;
}

#flatNav.scrolled .nav-logo {
    color: var(--primary);
}

.nav-logo-icon {
    width: 34px;
    height: 34px;
    flex-shrink: 0;
    object-fit: contain;
    display: block;
}

.nav-logo-text {
    font-weight: 700;
    font-size: 1.2rem;
    letter-spacing: -0.02em;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-links a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 200ms ease;
    letter-spacing: -0.01em;
}

.nav-links a:hover {
    color: white;
}

#flatNav.scrolled .nav-links a {
    color: var(--text-secondary);
}

#flatNav.scrolled .nav-links a:hover {
    color: var(--primary);
}

.btn-nav-signin {
    background: rgba(255, 255, 255, 0.15);
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.25);
    padding: 0.5rem 1.35rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all 200ms ease;
    backdrop-filter: blur(4px);
    font-family: inherit;
}

.btn-nav-signin:hover {
    background: rgba(255, 255, 255, 0.25);
    border-color: rgba(255, 255, 255, 0.4);
    transform: translateY(-1px);
}

#flatNav.scrolled .btn-nav-signin {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
    backdrop-filter: none;
}

#flatNav.scrolled .btn-nav-signin:hover {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
}


/* ==========================================================================
   Burger / Mobile Menu
   ========================================================================== */

.burger {
    display: none;
    flex-direction: column;
    gap: 5px;
    width: 26px;
    cursor: pointer;
    padding: 4px 0;
}

.burger-stripe {
    width: 100%;
    height: 2.5px;
    border-radius: 2px;
    background: white;
    transition: background 300ms ease;
}

#flatNav.scrolled .burger-stripe {
    background: var(--text);
}

@media (max-width: 768px) {
    .nav-links a,
    .nav-links .btn-nav-signin {
        display: none;
    }

    .burger {
        display: flex;
    }
}

#hamburgerMenu {
    position: fixed;
    top: 0;
    right: 0;
    z-index: 10000;
    background: white;
    padding: 1.5rem 2rem;
    border-radius: 0 0 0 var(--radius-xl);
    box-shadow: -4px 4px 24px rgba(0, 0, 0, 0.12);
    display: flex;
    flex-direction: column;
    gap: 1rem;
    min-width: 240px;
}

#hamburgerMenu a {
    color: var(--text);
    text-decoration: none;
    font-size: 1rem;
    font-weight: 500;
    padding: 0.5rem 0;
    transition: color 200ms ease;
    font-family: 'Inter', sans-serif;
}

#hamburgerMenu a:hover {
    color: var(--primary);
}

#hamburgerMenu .btn-nav-signin {
    display: block;
    background: var(--primary);
    color: white;
    border: none;
    text-align: center;
    padding: 0.65rem 1.5rem;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    margin-top: 0.5rem;
}

.close-burger {
    align-self: flex-end;
    cursor: pointer;
    width: 28px;
    height: 28px;
    color: var(--text-muted);
    transition: color 200ms ease;
}

.close-burger:hover {
    color: var(--text);
}

.close-burger svg {
    width: 100%;
    height: 100%;
}


/* ==========================================================================
   Hero Section
   ========================================================================== */

.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 4rem 2rem 5rem;
    background: linear-gradient(145deg, #084B6E 0%, #0B6E99 40%, #0E8AB5 70%, #1A96C8 100%);
    overflow: hidden;
    width: 100%;
    color: white;
    scroll-margin-top: 0;
    margin-bottom: 0;
    font-size: 1rem;
}

.hero-bg-shapes {
    position: absolute;
    inset: 0;
    overflow: hidden;
    pointer-events: none;
}

.hero-shape {
    position: absolute;
    border-radius: 50%;
    background: white;
}

.hero-shape-1 {
    width: 650px;
    height: 650px;
    top: -250px;
    right: -150px;
    opacity: 0.04;
}

.hero-shape-2 {
    width: 450px;
    height: 450px;
    bottom: -150px;
    left: -100px;
    opacity: 0.05;
}

.hero-shape-3 {
    width: 180px;
    height: 180px;
    top: 35%;
    left: 12%;
    opacity: 0.03;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 860px;
    animation: heroFadeIn 0.8s ease-out;
}

@keyframes heroFadeIn {
    from {
        opacity: 0;
        transform: translateY(24px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.45rem 1.1rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 100px;
    font-size: 0.8rem;
    font-weight: 500;
    margin-bottom: 1rem;
    border: 1px solid rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(4px);
    letter-spacing: 0.01em;
}

.hero-badge svg {
    opacity: 0.7;
    flex-shrink: 0;
}

.hero-title {
    font-size: clamp(3rem, 8vw, 4.75rem);
    font-weight: 800;
    letter-spacing: -0.04em;
    line-height: 1.05;
    margin-bottom: 1rem;
}

.hero-subtitle {
    font-size: clamp(1.05rem, 2.5vw, 1.4rem);
    font-weight: 400;
    opacity: 0.85;
    line-height: 1.5;
    margin-bottom: 1.5rem;
}

.hero-description {
    font-size: 1rem;
    opacity: 0.65;
    line-height: 1.7;
    /* max-width: 540px; */
    margin: 0 auto 2.75rem;
}

.hero-actions {
    display: flex;
    gap: 0.85rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn-hero-primary {
    background: white;
    color: var(--primary);
    border: none;
    padding: 0.85rem 2rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 250ms ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-family: inherit;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1);
}

.btn-hero-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.15);
}

.btn-hero-outline {
    background: transparent;
    color: white;
    border: 1.5px solid rgba(255, 255, 255, 0.35);
    padding: 0.85rem 2rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 250ms ease;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    font-family: inherit;
}

.btn-hero-outline:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.55);
    transform: translateY(-2px);
}

/* Hover-only links: look like normal text until hover */
.hover-link {
    color: inherit;
    text-decoration: none;
}

.hover-link:hover {
    text-decoration: underline;
}

.hero-badge .hover-link:hover {
    color: white;
}

.footer-text .hover-link {
    color: rgba(255, 255, 255, 0.7);
}

.footer-text .hover-link:hover {
    color: #58B4E0;
    text-decoration: underline;
}


/* ==========================================================================
   Hero Banner Image
   ========================================================================== */

.hero-banner {
    position: relative;
    z-index: 1;
    max-width: 860px;
    width: 90%;
    margin-top: 2.25rem;
    animation: bannerSlideUp 0.9s ease-out 0.2s both;
}

.hero-banner img {
    width: 100%;
    height: auto;
    border-radius: var(--radius-xl);
    box-shadow:
        0 24px 80px rgba(0, 0, 0, 0.25),
        0 0 0 1px rgba(255, 255, 255, 0.1);
    display: block;
}

@keyframes bannerSlideUp {
    from {
        opacity: 0;
        transform: translateY(32px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 768px) {
    .hero-banner {
        margin-top: 2rem;
        width: 95%;
    }
}


/* ==========================================================================
   Sections (shared)
   ========================================================================== */

.section {
    padding: 6rem 2rem;
    width: 100%;
    overflow: visible;
    scroll-margin-top: 4rem;
    color: var(--text);
    font-size: 1rem;
    margin-bottom: 0;
}

.section-alt {
    background: var(--bg-alt);
}

.section-inner {
    max-width: 1100px;
    margin: 0 auto;
}

.section-header {
    text-align: center;
    margin-bottom: 3.5rem;
}

.section-label {
    display: inline-block;
    background: var(--accent-light);
    color: var(--accent);
    font-weight: 600;
    font-size: 0.78rem;
    padding: 0.3rem 0.9rem;
    border-radius: 100px;
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.section-title {
    font-size: 2.15rem;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.025em;
    margin-bottom: 0.65rem;
    line-height: 1.2;
}

.section-subtitle {
    font-size: 1.05rem;
    color: var(--text-secondary);
    max-width: 480px;
    margin: 0 auto;
    line-height: 1.5;
}


/* ==========================================================================
   Step Cards (How It Works)
   ========================================================================== */

.steps-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.75rem;
}

@media (max-width: 768px) {
    .steps-grid {
        grid-template-columns: 1fr;
        max-width: 420px;
        margin: 0 auto;
    }
}

.step-card {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: 2.25rem 1.75rem;
    text-align: center;
    border: 1px solid var(--border);
    transition: all 350ms ease;
    position: relative;
}

.step-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: transparent;
}

.step-number {
    position: absolute;
    top: 1rem;
    left: 1rem;
    width: 28px;
    height: 28px;
    background: var(--bg-alt);
    color: var(--primary);
    border-radius: var(--radius-sm);
    font-weight: 700;
    font-size: 0.8rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.step-icon {
    width: 68px;
    height: 68px;
    margin: 0.5rem auto 1.5rem;
    color: var(--primary);
}

.step-icon svg {
    width: 100%;
    height: 100%;
}

.step-card h3 {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 0.65rem;
    letter-spacing: -0.01em;
}

.step-card p {
    font-size: 0.925rem;
    color: var(--text-secondary);
    line-height: 1.65;
}


/* ==========================================================================
   Features Row
   ========================================================================== */

.features-row {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

@media (max-width: 768px) {
    .features-row {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
}

.feature-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1.5rem;
    border-radius: var(--radius-md);
    transition: background 200ms ease;
}

.feature-item:hover {
    background: rgba(255, 255, 255, 0.6);
}

.feature-icon {
    width: 44px;
    height: 44px;
    flex-shrink: 0;
    background: white;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    box-shadow: var(--shadow-sm);
}

.feature-icon svg {
    width: 22px;
    height: 22px;
}

.feature-text h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 0.3rem;
    letter-spacing: -0.01em;
}

.feature-text p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.55;
}


/* ==========================================================================
   Citation
   ========================================================================== */

.citation-paper-link-wrap {
    text-align: center;
    margin-bottom: 1.25rem;
}

.citation-paper-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 600;
    transition: color 200ms ease;
}

.citation-paper-link:hover {
    color: var(--primary-dark);
}

.citation-paper-link svg {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
}

.citation-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.75rem 2rem;
    max-width: 680px;
    margin: 0 auto;
    overflow-x: auto;
    position: relative;
}

.citation-card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1rem;
}

.citation-copy-hint {
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
}

.citation-copy-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.4rem 0.75rem;
    background: var(--bg-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 200ms ease;
    font-family: inherit;
}

.citation-copy-btn:hover {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

.citation-copy-btn.copied {
    background: var(--accent);
    border-color: var(--accent);
    color: white;
}

.citation-copy-icon {
    width: 14px;
    height: 14px;
    flex-shrink: 0;
}

.citation-card pre {
    margin: 0;
}

.citation-card code {
    font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
    font-size: 0.825rem;
    line-height: 1.75;
    color: var(--text);
    white-space: pre;
}


/* ==========================================================================
   Floating Action Buttons
   ========================================================================== */

.fab {
    position: fixed;
    right: 20px;
    z-index: 10000;
    display: inline-flex;
    align-items: center;
    gap: 7px;
    padding: 0.6rem 1.15rem;
    border-radius: var(--radius-md);
    font-size: 0.825rem;
    font-weight: 500;
    text-decoration: none;
    color: white;
    transition: all 200ms ease;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.15);
    font-family: 'Inter', sans-serif;
}

.fab svg {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
}

.fab:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 22px rgba(0, 0, 0, 0.2);
}

.fab-guide {
    bottom: 68px;
    background: #059669;
}

.fab-guide:hover {
    background: #047857;
}

.fab-support {
    bottom: 20px;
    background: var(--primary);
}

.fab-support:hover {
    background: var(--primary-dark);
}


/* ==========================================================================
   Back to Top
   ========================================================================== */

.back-to-top-btn {
    position: fixed;
    bottom: 124px;
    right: 20px;
    z-index: 10000;
    background: var(--card-bg);
    color: var(--text);
    border: 1px solid var(--border);
    padding: 0.5rem 1.1rem;
    border-radius: var(--radius-md);
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 5px;
    box-shadow: var(--shadow-md);
    transition: all 200ms ease;
    font-family: 'Inter', sans-serif;
}

.back-to-top-btn:hover {
    background: var(--bg-alt);
    transform: translateY(-2px);
}


/* ==========================================================================
   Footer
   ========================================================================== */

footer {
    background: #0A2540;
    color: rgba(255, 255, 255, 0.7);
    padding: 3rem 2rem 2rem;
}

.footer-inner {
    max-width: 900px;
    margin: 0 auto;
}

.footer-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1.75rem;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    color: white;
    font-weight: 700;
    font-size: 1.1rem;
}

.footer-logo-icon {
    width: 28px;
    height: 28px;
    flex-shrink: 0;
}

.footer-logo-text {
    letter-spacing: -0.02em;
}

.footer-links {
    display: flex;
    gap: 1.75rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.5);
    text-decoration: none;
    font-size: 0.85rem;
    font-weight: 400;
    transition: color 200ms ease;
}

.footer-links a:hover {
    color: rgba(255, 255, 255, 0.85);
}

.footer-divider {
    border: none;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    margin-bottom: 1.5rem;
}

.footer-bottom {
    text-align: center;
}

.footer-text {
    font-size: 0.85rem;
    line-height: 1.6;
    margin-bottom: 0.75rem;
}

.footer-text a {
    color: #58B4E0;
    text-decoration: none;
}

.footer-text a:hover {
    text-decoration: underline;
}

.footer-copyright {
    font-size: 0.75rem;
    opacity: 0.4;
}

@media (max-width: 768px) {
    .footer-top {
        flex-direction: column;
        gap: 1.25rem;
        text-align: center;
    }

    .footer-links {
        gap: 1.25rem;
    }
}


/* ==========================================================================
   Login Modal
   ========================================================================== */

.landing-page .login-modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 10001;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
    background: rgba(10, 37, 64, 0.55);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
}

.landing-page .login-modal {
    font-family: 'Inter', sans-serif;
    border-radius: var(--radius-xl);
    padding: 2rem 2.25rem;
    border: 1px solid var(--border);
    box-shadow: 0 24px 64px rgba(0, 0, 0, 0.2);
    background: white;
    max-width: 400px;
    width: 100%;
    position: relative;
}

.login-modal-header {
    text-align: center;
    margin-bottom: 1.5rem;
}

.login-logo-icon {
    width: 44px;
    height: 44px;
    margin-bottom: 1rem;
}

.landing-page .login-modal-title {
    font-weight: 700;
    font-size: 1.3rem;
    color: var(--text);
    margin-bottom: 0.35rem;
}

.login-modal-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.landing-page .login-modal-close {
    position: absolute;
    top: 0.75rem;
    right: 1rem;
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.75rem;
    line-height: 1;
    cursor: pointer;
    padding: 0.25rem;
    transition: color 200ms ease;
}

.landing-page .login-modal-close:hover {
    color: var(--text);
}

.landing-page .login-form label {
    display: block;
    font-weight: 500;
    color: var(--text);
    font-size: 0.85rem;
    margin-top: 0.85rem;
    margin-bottom: 0.3rem;
}

.landing-page .login-form input {
    width: 100%;
    border-radius: var(--radius-sm);
    border: 1.5px solid var(--border);
    padding: 0.6rem 0.85rem;
    font-size: 0.95rem;
    transition: border-color 200ms ease, box-shadow 200ms ease;
    font-family: 'Inter', sans-serif;
    box-sizing: border-box;
    color: var(--text);
    background: white;
}

.landing-page .login-form input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(11, 110, 153, 0.1);
}

.landing-page .login-form input::placeholder {
    color: var(--text-muted);
}

.btn-modal-submit {
    display: block;
    width: 100%;
    margin-top: 1.25rem;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-family: 'Inter', sans-serif;
    padding: 0.7rem 1.5rem;
    font-size: 0.95rem;
    cursor: pointer;
    transition: all 200ms ease;
}

.btn-modal-submit:hover {
    background: var(--primary-dark);
}

.login-first-time {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border);
}

.login-first-time-note {
    font-size: 0.85rem;
    color: var(--accent);
    font-weight: 500;
    margin-bottom: 0.25rem;
}

.login-error {
    color: #DC2626;
    font-size: 0.85rem;
    margin-top: 0.5rem;
    font-weight: 500;
}


/* ==========================================================================
   Responsive
   ========================================================================== */

@media (max-width: 768px) {
    .hero {
        padding: 7rem 1.5rem 3.5rem;
        min-height: 90vh;
    }

    .hero-title {
        font-size: 2.75rem;
    }

    .hero-description {
        font-size: 0.925rem;
    }

    .hero-badge {
        font-size: 0.72rem;
    }

    .section {
        padding: 4rem 1.5rem;
    }

    .section-title {
        font-size: 1.7rem;
    }

    .section-subtitle {
        font-size: 0.95rem;
    }

    .citation-card {
        padding: 1.25rem;
    }

    .citation-card code {
        font-size: 0.75rem;
    }

    .fab {
        padding: 0.5rem 0.95rem;
        font-size: 0.78rem;
    }

    .back-to-top-btn {
        font-size: 0.75rem;
        padding: 0.4rem 0.85rem;
    }
}

@media (max-width: 480px) {
    #flatNav {
        padding: 0.75rem 1rem;
    }

    #flatNav.scrolled {
        padding: 0.5rem 1rem;
    }

    .hero {
        padding: 6rem 1.25rem 3rem;
        min-height: 85vh;
    }

    .hero-title {
        font-size: 2.25rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-actions {
        flex-direction: column;
        align-items: center;
    }

    .btn-hero-primary,
    .btn-hero-outline {
        width: 100%;
        justify-content: center;
        max-width: 280px;
    }

    .section {
        padding: 3rem 1.25rem;
    }

    .section-header {
        margin-bottom: 2.5rem;
    }
}